Pipe machining tool



A 19, 1952 J- T. MONTGOMERY 2 ,607,376

PIPE MACHINING TOOL I Filed April 16, 1949 INVENTOR. dob/1 '7. Monfgomery ATTO RNE Y Patented Aug. 19, 1952 OFFICE P'IPE MACHINING 'rooL 'John T. Montgomery, San Francisco, Calif., as-

signor to Pilot .Manufacturing Company, San

a V Francisco, Calif.,'acopartnership 1 v a a iahplication April 16, 1949, SerialNo. 87,941

The present invention relates to improvements in a pipe machining tool and has particular reference'to a tool-for machining a tapered or cylindrical finish on the end of asbestos cemerit pipe and forfacing the endof the pipe.

"My tool comprises ini'ts principal'feature's a shaft having means for anchoring thelsame to theinside of the pipe and a cutter head r-evolvable on the shaft, and the principal" object of the invention is to 'provide an anchoring means for the shaft which automatically centers the shaft with respect to the pipe.

A further object of the inventionis to provide an anchoring means which will readily compensate for slight inaccuracies in the inner face of the pipe and will bring .the shaft substantially into the median center which may be defined as an axis closest to being the common axis of all irregularities.

1 It is further proposed to provide an anchoring means which may be adjusted to accommodate a wide range of sizes and will support itself in a curved'segment of the pipe.

It is further proposed in the present invention to provide a special cutter head which'will automatically bring the cutter into the correct position'with respect to the pipe, regardless of the size of the latter. j

And"finally,'it'is'proposed to provide a tool of the character described that is relatively simple in construction and may be applied to the pipe with little effort. Z

Further objects and advantages of my invention will appear as the specification proceeds, and the novel features of my "invention will be fully defined in the claims attached hereto.,

fThe preferred form of my invention is illustrated in the accompanying drawing, in which:

Figure 1 shows an outer end view of the tool as applied to a pipe,

Figure 2, an inner end view of the tool, and

--'Figure'3, aside view of the tool as applied to the pipe, certain portions being shown in section.

While I have shown only the preferred form of my invention, I wish tohave it understood that variouschanges and modifications may be made within; the scopeof the claims attached hereto without departing from the spirit of theainventiorn; f

, Referring to the drawing in detail, my tool comprises in its principal features a shaft I having anchoring means 2 attached thereto, and a cutter head 3 carrying a cutter 4. The tool illustrated was'de signed for pipes rangingfrom 3 inches to B inchesindiameter and the shaft I may be s'olaiins. (01. 144-205) approximately three-quarters of an inch in diameter and should be of sufficient length to allow of approximately one-half for carrying the anchoring means within the pipe while the other half projects. from; the end ofthe pipetolcarry the cutter head.

The anchoring means comprises its prin cipal features a bearing 5 with a knurled outer fac e in which the shaft revolves but is held against endwise movement, a nut 6 threaded upon the inner end of the shaft, and cooperative fingers I and} pivoted to the bearing and the nut as at 9 and I0 and to eachother intermediate their length as at H.

:1 preferably provide three radial sets of fingers spaced 120 apart, eachset comprising a middle finger 1 attached to" the bearing and two outer fingers 8 straddling the middle-finger.

The outer end of the shaftehas acrank l2 pivoted thereto as at I3, the cranlrbeing swingable in a slot inthe shaft between the rectangualinement with'the shaft 5 i 1 p v It will be noticed that with the tool in the position shown in Figure 3 as mounted inthe pipe I I the fingers may be spread and contractedl by a turning movement of the shaft with the bearing 5 held stationary which'cau'ses the nut 6 to move toward or away from the bearing depending upon-the direction of rotation.

It will be --notec l that theextreme ends of the fingers may thus be brought into anchoring contact with the inner face of the pipe at nine different points, each set havingthree contact points and the three setsbeing spaced circumferentially by i J M It will also be noted that the pivots -9 and iii of thefingers are arranged relatively close to the inner edges of the. latter, while the pivot H of each set is relatively close to the outer edges of .the fingers. "Thi's 'prevents thepiviotll from ever reaching .a'. dead. an position with respect to the pivots 9 and ID and facilitates initial opening of the fingers from their most collapsed position adjacenttheshaftff a While the fingers have been described as moving in radial planes, it willbe "noted, that only the middle Ifinger strictly speaking 'in ov'es in the radialv planeof the axis of theshaftlwhile the two outer "fingers move parallel to themiddle finger. Due 'to thefact thatthe inner surface of thepipe'is'curvedit is apparent that if the contact faces of' thefingers moved Xactly-in-straight planes paralleling the axis of the shaft,- th-edouble fingers would strike the innerface 0f the pipe lar position shown inFigure 3' and a position of somewhat different from the contact face of each inner finger.

, In their extreme ends which would constitute the contact faces in a large pipeth'e curvatures are drawn to the same are because no com ense} tion for the pipe curvature is needed. I-Idwever,

game

as the contact faces recede from theextreme I ends, as in the case where the device is-usedin connection with a pipe of smaller diameter and the pipe curvature becomes more pronounced, the double fingersarefdrawnto a curve of progressively increasing radius; as shown in Tig ure 3. This results inthe (:01,1tf tct points of the double fingers receding more quickly than those of the single fingers, on a collapsingmovement.

The cutter head 3 comprises a handle- I! con- 'sisting of a hub'l8 revolvable on thesihaft land two arms 19 projecting from't-he hub 'in opposite directions.

tangular block 24 provided with suitable holes 25 and 26 adapted to receive "suitable bolts 21 for securing the cutter bladeZG upon the cutter mounting. It will be noted that the two holes 25 are slightly disa ligned tojbring the cutting edge of the bladeinto inclined position with respect to the edge of the blade mounting for effecting a tapered cut on the end of the pipe, while the holes 26 are alined so thatwhen the blade is secured by meansofthese two holes, a cylindrical cut will be obtained. It is: apparent that the mounting block is reversible in its slot and may readily be transferred to the slot in the otherarm. M H I The manner of using theinvention will be readily understood from the foregoing description. When the end of a pipe is to be trimmed the operator will usually first set the shaft with respect to the pipe. This he can do by introducing the anchoring means into the pipe, with the bearing projecting sufficiently far to form a hand-hold. He then'turns the shaft bymeans of the crank 12 until the fingers contact theinner face of the pipe and firmly anchor the shaft.

' Next he will swing the crank l2 into a position of alinement with the shaft 1 and slide the handle over the crank upon the shaft. V

Having previously set the'cutter at the proper distance from the center of rotation, he. then turns the handle, crowding the same. towards the pipe until the desired trim has been obtained. The cutter head may then be removed by again slidingthe same over the alined crank l2, and the anchoring means may be released by a turning movement of theshaft l, with the bearing 5 held against rotary motion.

It will be noted that the anchoring means is particularly efiicient and readily adapts itself to small inacouraciesin the shape of the pipe in view of the fact that it provides nine different points of contact, three at one end and six at the other end, and also makes provision for the pipe curvatures by the, correct shaping of the contact curvesatl5andl6. y p

The handles are offset with respect to a diameter to bring each of the arms slightly behind the diameter in its rotary course and to allow the blade to be properly positioned, slightly ahead of H the diameter, as clearly shown in Figure 2, to

provide. the proper rake. .511 le l i l- 1. In a pipe chining tool of the character described, a bearing member, a shaft revolvable therein and held against endwise motion with.

respect thereto, a nut member threaded on one end of the shaft, radial sets of cooperative fingers pivoted in the two members respectively and having free ends, and pivots connecting the fingers of each set' intermediate their lengtl' s, whereby the free endsjof thefingers are made to movetoward or awayfrbm'thcgshaftin response to a turning movementof the latter in its'b'earingmemberb e H I 2. In a pipe machining to'olof the character described, a bearing member, a 'shaft' revol'vable therein and held againstendwise motion with respect thereto, a nutmember. threaded -onv one end of the shaft, radial sets of cooperative fingers pivoted in the saidfrn'embers respectively and having free ends, and pivots connecting the fingers of each set' intermediate their lengths, whereby the free ends of; the fingers ma'ybe' made to expand 'against1tlieinside face of a pipe surrounding the same when the shaft .is

turned in its bearing memberthe free ends 'of the fingers having longitudinally curved contact faces.

.3. In a pipe machining tool of thecharacter described, a bearing member, a shaftrevolvable' therein and held against end'wisei motion with respect thereto, a nut m iiber; threaded on one end of the shaft. radial sets of cboliielfativ fingers pivoted in the said mrribersrespectively and having free ends, and pivots connecting the fingers of each set ntermediate? tn r21 gths. Wherebythe free ndsof the fir'igfers'm made to expand against the insidef'ace 'of'apipesui' rounding the same when the shaft'fis turned in its bearing member" "the weekends of the fii'gfers havinglongitudinall' c ve c t faes',, af1d each set of fingers com rising efingr pivoted to one of said manilarsand, 7 fifigels pivoted to the other 'member'ana 'stracdlnigiw'e former finger V "dm- 4. In a pipe machining tool oflthe ch'aracter described, a bearing member a haar voivame therein andheldagai-ns t endwise motion with respect thereto, a nut member-threaded on-one end of the shaft, rad was. of, cooperative straight fingerspivotedJini the; said members respectively and. having free :ends, zandzpivots connecting the 'fihgers of eaclf'set intermediate their lengths, whereby the free' Tends "of the fingers may be made to expand against the inside face-of a pipe surrounding the samewhen the shaft is turned in'it's bearl: A W trac tedi to a position shaft and in alinement I necting pivot being 0 alined so as to prevent locking of the fingers in dead center position.

5. In a pipe machining tool of the character described, a bearing member, a shaft revolvable therein and held against endwise motion with respect thereto, a nut member threaded on one end of the shaft, radial sets of straight cooperative fingers pivoted in the two members respec tively and having free ends, the fingers being pivoted to the two members immediately adjacent the shaft, and pivots connecting the fingers of each set intermediate their lengths, whereby the free ends of the fingers are made to move toward or away from the shaft in response to a turning movement of the latter, the fingers being dimensioned for accommodation between the two bearing members immediately adjacent the shaft and in alined relation with each other in the extreme movement of the free ends toward the shaft.

6. In a pipe machining tool of the character described, a bearing member, a shaft revolvable therein and held against endwise motion with respect thereto, a nut member threaded on one end of the shaft, radial sets of straight cooperative fingers pivoted in the two members respectively and having free ends, the fingers being pivoted to the two members immediately adjacent the shaft, and pivots connecting the fingers of each set intermediate their lengths, whereby the free ends of the fingers are made to move toward or awayfrom the shaft in response to a turning movement of the latter, the fingers being dimensioned for accommodation between the two bearing members immediately adjacent the shaft and in alined relation with each other in the extreme movement of the free ends toward the shaft, and the connecting pivot being off-set with respect to the finger-anchoring pivots when the fingers are alined adjacent the shaft so as to prevent locking of the fingers in dead center position.

7. In a pipe machining tool of the character described, a pair of bearing members, a shaft revolvable therein, cooperative means on. the

shaft and at least one of the bearing members for effecting relative movement of the bearing members toward and away from each other when the shaft is rotated, radial sets of straight cooperative fingers pivoted in the two 1 Number 6 7 members respectively and having free ends, the fingers being pivoted to the two members immediately adjacent the shaft, and pivots connecting the fingers of each set intermediate their lengths, whereby the free ends of the fingers shaft and at least one of the bearing members for effecting relative movement of the bearing members toward and away from each other when the shaft is rotated, radial sets of straight cooperative fingers pivoted in the two members respectively and having free ends, the fingers being pivoted to the two members immediately adjacentthe shaft, and pivots connecting the fingers of each set intermediate their lengths, whereby the free ends of the fingers are made to move toward or away from the shaft in response to a turning movement of the latter, the fingers being dimensioned for accommodation between the two bearing members immediately adjacent the shaft and in alined relation with each other in the extreme movement of the free ends to ward the shaft, and the connecting pivot being oiT-set with respect to the finger-anchoring pivots when the fingers are alined adjacent the shaft so as to prevent lockin of the fingers in dead center position.

JOHN T. MQNIGOMERY.

REFERENCES CITED UNITED STATES PATENTS Name Date 764,341 Bond July 5, 1904 1,155,337 Burns Oct. 5, 1915 1,823,959 Steinmayer Sept. 22, 1931 1,985,757 Abramsen Dec. 25, 1934 1,993,561 'Meglitz Mar. 5, 1935 2,080,906 Boyer May 18, 1937 

